2) Once you download it, tap any Office app to open it. Swipe through the introduction, and tap Sign In.3) To use the extra features in the app, on the Sign in page, type the personal Microsoft account or work or school account associated with your Office 365 subscription, and then tap Next.

4) Type your Password, and then tap Sign in.

After you complete the sign in process on one of the Office apps, your account and the OneDrive for Business service is automatically added to the other Office apps installed on your iPhone or iPad.

5) Tap Create and Edit Documents to start working on your documents.

Opening documents in the app

Tap the service where you want to view your files. For example, to view Word, Excel, or PowerPoint documents, tap Open > OneDrive - Personal or tap Open > OneDrive - your business name and you'll see the list of files you saved to OneDrive or OneDrive for Business. The files you see are specific to the app you opened them in. For example, if you opened the Word app, you'll only see Word documents or if you opened the Excel app, you'll see Excel spreadsheets.

To view any OneNote note books you saved to OneDrive or OneDrive for Business, tap + Open Existing.